Orthopedic involvement in antiphospholipid syndrome.

Antiphospholipid syndrome (APS) is a common autoimmune disease, manifested by vascular thrombosis and fetal loss in the presence of antiphospholipid antibodies. Orthopedic involvement is a relatively novel and under-recognized feature of APS. In this article we review the association of primary, secondary, and catastrophic APS with diverse orthopedic conditions, including osteonecrosis in adult and pediatric patients, bone marrow necrosis, nontraumatic fractures, and some other disorders.